Paleosols and paleoenvironments of the middle Miocene, Maboko Formation, Kenya.
Paleosols and paleoenvironments of the middle Miocene, Maboko Formation, Kenya.
复制标题
肯尼亚马博科组中中新世的古土壤和古环境。
DOI：
10.1006/jhev.2002.0553
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发表时间：
2002
影响因子：
3.2
通讯作者：
M. Mccrossin
中科院分区：
文献类型：
--
作者：
G. Retallack;J. Wynn;B. Benefit;M. Mccrossin
肯尼亚西南部马博科岛和马吉瓦崖的中中新世（15 Ma）马博科组（Maboko Formation）中发现了大量已知最早的长尾猴类（Macapithecus macinnesi）和肯尼亚古猿类（Kenyapithecus africanus）化石，以及罕见的原猴（Simiolus leakeyorum，cf. Limnopithecus evansi）和山猿类（Mabokopithecus clarki，M. pickfordi），和galagids（Komba winamensis）。特定的栖息地偏好可以从不同类型的古土壤（土壤类型）中的大量灵长类化石中得到解释。含化石的土褐色古土壤与铁锰结核（Yom土壤型）类似于季节性积水洼地（dambo）的现代土壤。其碎屑结构和丰富的细根痕迹，以及分散的大型钙质根结核表明以前的植被季节性潮湿，树木繁茂的草原。其他含盐古土壤是nyika古林地（Ratong）和早期演替河岸林地（Dhero）的证据。没有化石被发现在Mogo古土壤解释为含盐灌丛土壤。非常浅的钙质层（在Yom，Ratong和Mogo古土壤中）和钠蒙脱石（在Mogo）是干燥的古气候的证据（300-500 mm MAP=平均年降水量）。这是最干燥的古气候和最开放的植被，但推断为任何肯尼亚中新世猿或猴子的栖息地。古猿在丹波森林草原（Yom）和河岸林地（Dhero）分布丰富，与现代黑长尾猴的分布相似。肯尼亚古猿在所有这些古土壤中都有分布，但它是尼卡古土壤（拉通）中最常见的灵长类动物，与今天的狒狒和猕猴相当。Mabokopithecus实际上仅限于河岸林地古土壤（Dhero），Simiolus有类似的，但稍微更广泛，分布。猕猴和猿猴的栖息地偏好与现代疣猴和白眉猴相似。在丹波森林草原古土壤（Yom）中发现了一个Komba的标本，这是一个更像生活在塞内加尔而不是热带雨林的Galagids的栖息地。向非森林栖息地的转移可以解释猕猴的陆地适应，以猕猴科辐射为基础，肯尼亚古猿的基础，以人科辐射为基础。这两个类群都不同于早中新世树栖proconsulines，oreopithecines和galagids。
The middle Miocene (15 Ma) Maboko Formation of Maboko Island and Majiwa Bluffs, southwestern Kenya, has yielded abundant fossils of the earliest known cercopithecoid monkey (Victoriapithecus macinnesi), and of a kenyapithecine hominoid (Kenyapithecus africanus), as well as rare proconsuline (Simiolus leakeyorum, cf. Limnopithecus evansi) and oreopithecine apes (Mabokopithecus clarki, M. pickfordi), and galagids (Komba winamensis). Specific habitat preferences can be interpreted from large collections of primate fossils in different kinds of paleosols (pedotypes). Fossiliferous drab-colored paleosols with iron-manganese nodules (Yom pedotype) are like modern soils of seasonally waterlogged depressions (dambo). Their crumb structure and abundant fine root-traces, as well as scattered large calcareous rhizoconcretions indicate former vegetation of seasonally wet, wooded grassland. Other fossiliferous paleosols are evidence of nyika bushland (Ratong), and early-successional riparian woodland (Dhero). No fossils were found in Mogo paleosols interpreted as saline scrub soils. Very shallow calcic horizons (in Yom, Ratong, and Mogo paleosols) and Na-montmorillonite (in Mogo) are evidence of dry paleoclimate (300-500 mm MAP=mean annual precipitation). This is the driest paleoclimate and most open vegetation yet inferred as a habitat for any Kenyan Miocene apes or monkeys. Victoriapithecus was abundant in dambo wooded grassland (Yom) and riparian woodland (Dhero), a distribution like that of modern vervet monkeys. Kenyapithecus ranged through all these paleosols, but was the most common primate in nyika bushland paleosols (Ratong), comparable to baboons and macaques today. Mabokopithecus was virtually restricted to riparian woodland paleosols (Dhero), and Simiolus had a similar, but marginally wider, distribution. Habitat preferences of Mabokopithecus and Simiolus were like those of modern colobus monkeys and mangabeys. A single specimen of Komba was found in dambo wooded grassland paleosol (Yom), a habitat more like that of the living Senegal bushbaby than of rainforest galagids. A shift to non-forest habitats may explain the terrestrial adaptations of Victoriapithecus, basal to the cercopithecid radiation, and of Kenyapithecus, basal to the hominoid radiation. Both taxa are distinct from earlier Miocene arboreal proconsulines, oreopithecines and galagids.
影响因子：
64.8
作者：
Cerling, TE;Harris, JM;Ehleringer, JR
通讯作者：
Ehleringer, JR